Response of white clover (Trifolium repens L.) and ryegrass (Lolium perenne L.) to acid rain in situations of species interferences.

Pure stands of Trifolium repens L. N.Z. Huia and Lolium perenne L. S32 and mixtures of various densities and frequencies were treated with sulphuric acd solutions of pH 2.5, 3.5 and 5.6. The species yield was recorded over five sequential harvests. Multifactorial response equations were used to describe the behaviour of the species yield as a function of acidity and the density of both species. Predictions, made through these models, showed that the response of yield of these species to simulated acid rain treatments Varied greatly depending on the planting density, the time of harvesting and on whether the plants were growing in monoculture or in mixture. This suggests that it is not sufficient to consider the effects of experimentally applied acid rain on single individuals or low density stands, since the results obtained will not reflect the response in a close canopy sward.

New allele frequency database: http://www.allelefrequencies.net.

A new website (http://www.allelefrequencies.net) has been compiled to execute the frequency of alleles at various polymorphic regions of different populations in the field of histocompatibility and immunogenetics. Data for HLA alleles has been added but this will be extended to include frequency data of polymorphisms in other immunogenetic regions, e.g. cytokines, KIR receptors, MIC.

The attachment, proliferation, and wound healing of endothelial and smooth muscle cells on nitinol thin film in vitro.

Nitinol (TiNi) thin film is a potentially useful material for various clinical applications, e.g., vascular stents. In this study we examined the biological functions of bovine endothelial cell (BAEC) and bovine smooth muscle cells (BSMC) on 1-mum thick amorphous TiNi films. BAEC and BSMC both attached on TiNi film, and exhibited increased cell spreading in the presence of serum containing media. Both cell types had decreased cell proliferation on TiNi as compared to glass control; however, BAEC had significantly greater proliferation rate than BSMC on TiNi. In an in vitro wound model, BSMC migrated faster than BAEC, resulting in a quicker closure of the monolayer. These results provide important insights into the interactions of vascular cells and TiNi thin film, and will help us to optimize the surface properties of TiNi film for applications in the vascular system.